When it's dark there are several ways you can take a shot which is properly exposed:
- Increase aperture
- Use a long shutter speed
- Increase ISO
- Use a flash
I will treat the above points one-by-one for the situation you described.
Your lens has a maximum aperture of f/4 when at 55mm and f/5.6 when at 200mm. So to get the aperture as big as possible you should get as close as possible to the race track such that you use the lens close to the 55mm with f/4.
To increase your aperture, set your mode dial to
Manual, zoom out, and set your aperture to f/4.
Long shutter speed
For this option it is advisable that you use a tri-pod or some other stabilizing apparatus. Without it you will have camera-shake-blur.
As you're at a car race keep in mind that very long shutter speeds will blur out the motion of the car.
NASCAR cars have an average velocity of
130 km/hr = 36.1 m/s
If you use a shutter speed of
1/30s this would mean that the car moves
36.1*(1/30) = 1.2m while you take a shot. Depending on your distance to the car this might produce noticeable blur.
If you use a tri-pod, get one which enables you to rotate the camera around the vertical axis easily. This enables you to track the car with your camera, creating shots like these. An alternative to a tri-pod is a DIY stabilizer as described here.
To set the shutter speed on your camera, set the mode dial to
S priority or
By increasing the ISO value you turn up the gain of your camera sensor. This has the desirable result that the sensor outputs a stronger signal and the undesirable result that the sensor generates more noise. Depending on your own taste you can decide what is an acceptable level of noise and based on that you can set your ISO value.
On your camera the maximum ISO is 1600. Try it out before the race to see if this maximum setting generates an unacceptable amount of noise. Also see if you can remove the noise with a post-processing program.
Use a flash
Set-up and off-camera flash along the racing track which is (wireless) triggered by your camera when you release the shutter. I don't think this is a realistic option, as a flash might distract the driver, but who knows.
If you use a flash, try to use a long shutter speed nonetheless as this enables your camera to capture the natural light present at the scene.
S priority with a not too long shutter speed. Use a tri-pod.